News:



  • April 27, 2024, 01:24:36 AM

Login with username, password and session length

Author Topic: Clear coating - the final frontier !!  (Read 1830 times)

Offline Paul Smith

  • 24 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 5801
Clear coating - the final frontier !!
« on: December 22, 2023, 02:45:56 PM »
Having gone through the job of painting a plane, the final challenge is the two-part epoxy clear coat.  If bungled, all is lost.
I start out by clearing the shop, then clear coat the plane and leave the basement for the balance of the shift.
I mixed-up four tea spoons of Klass Kote just be on the safe side.  2.3 would have worked, but you sure can't stand to come up short.
Klass Kote keeps the paint on the plane and it doesn't cost me anything since I bought it in quarts at Toledo for an old scale project and this was left over.

I always let paint dry with the plane nose-up, so if it runs or drips it will go to the TE where it is easily removed.
Paul Smith

Offline Steve Berry

  • 24 supporter
  • Trade Count: (0)
  • Captain
  • *
  • Posts: 449
Re: Clear coating - the final frontier !!
« Reply #1 on: December 22, 2023, 02:49:17 PM »


I start out by clearing the shop....

How many gallons did that take, and how long do you think it'll take to sand out & buff?

Steve

Sent from my SM-N986U using Tapatalk


Offline Steve Berry

  • 24 supporter
  • Trade Count: (0)
  • Captain
  • *
  • Posts: 449
Re: Clear coating - the final frontier !!
« Reply #2 on: December 22, 2023, 02:49:59 PM »
Seriously, though...nice work!

Steve

Sent from my SM-N986U using Tapatalk


Offline Paul Smith

  • 24 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 5801
Re: Clear coating - the final frontier !!
« Reply #3 on: December 22, 2023, 05:38:36 PM »
I never sand & buff.

I build, paint, and fly.
Paul Smith

Offline Airacobra

  • Trade Count: (0)
  • Commander
  • ****
  • Posts: 292
Re: Clear coating - the final frontier !!
« Reply #4 on: December 23, 2023, 08:31:20 PM »
Is that system one that can be wet sanded and ultimately buffed out?
Keith Bryant

Offline C.T. Schaefer

  • Trade Count: (0)
  • Captain
  • *****
  • Posts: 712
Re: Clear coating - the final frontier !!
« Reply #5 on: December 24, 2023, 05:59:59 AM »
Handsome ship Paul!

Offline Dennis Toth

  • 2020 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 4228
Re: Clear coating - the final frontier !!
« Reply #6 on: December 24, 2023, 09:35:30 AM »
Paul,
Beautiful job. Could you detail the base and color paints you used? How did you apply them and the clear Klass Kote?

Best,   DennisT

Offline 944_Jim

  • 24 supporter
  • Trade Count: (0)
  • Captain
  • *
  • Posts: 854
Re: Clear coating - the final frontier !!
« Reply #7 on: December 24, 2023, 09:54:08 AM »
I'm extremely  curious/interested in what epoxy was used, and how does one keep it from cooking off in the painting equipment? What does one use as a thinner?

I can only guess one hour epoxy, thinned/sprayed fast, and then the tools are rapidly flushed with methanol/lacquer thinner before a detailed wash-out.

Offline Paul Smith

  • 24 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 5801
Re: Clear coating - the final frontier !!
« Reply #8 on: December 25, 2023, 06:16:11 AM »
Paul,
Beautiful job. Could you detail the base and color paints you used? How did you apply them and the clear Klass Kote?

Best,   DennisT

OK.

First I put Randolph dope on the wing with a brush.  I get at least some clear of the ribs to protect against the water I use to apply the silk. 
I sand the structure very smooth so the silk does not snag.
I cover in four separate parts: bottom, top, right and left.  Trying to use one or two pieces is nothing but trouble and wrinkles.
I spray the silk lightly with water and work of the wrinkles.  It's a matter if technique get the wrinkles out without pulling too hard and pulling in a warp.
At first I just dope the outline for two coats.  When the dope & water have dried I begin piling on the clear dope.  It takes me a minimum of six coats of clear.  Maybe more if it looks like it needs more.

The body is done like the wing before assembly.  It's a lot easier and better to mask and paint the body before final assembly.  Like the wing, the body gets a minimum of six coats of Randolph/Brodak clear.  Note: if you go to Randolph's web site they list Brodak as a dealer.  I mask the body and trim with Randolph colors using an air brush.   After very carefully mixing the quart of color I pour about four ounces into a GLASS thinning jar.  The dope needs to be very thin to go through my air brush.  I put about an ounce of thinned dope in the air brush jar and try to spray a sample.  It's often still too thick so I thin it some more.  It seems so watery-thin that it won't cover, but it does. 

Then I clear the spray head in a shot glass with lacquer thinner and dump the tinted thinner back into the thinning jar.  Zero waste!

When the wing and body are done I assemble them with 30-minute epoxy in several small applications, using gravity and a heat gun to get the epoxyinto every void.

I clear coat the body, tail and about two inches of the wing with Klass Kote used full strength.  I don't dare spray two-part epoxy.  Also, I'm afraid that thinner in the epoxy would attack the colors when I brush it on.  I use throw away brushes for the clear coat.  I doubt that I could clean the brush well enough to use it again and if I did the thinner would cost more than a new brush.

When I mix the Klass Kote I use two throw away plastic spoons for the parts A & B.  Using three spoons of each part for a plane this size means that a quart of each will last me forever.

This is not intended to be a 20-point front row PAMPA winner.  It's just for painting a plane to fly around and have it look good pretty good compared to other sport planes.

Paul Smith

Offline Dennis Toth

  • 2020 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 4228
Re: Clear coating - the final frontier !!
« Reply #9 on: December 25, 2023, 07:08:26 AM »
Paul,
Merry Christmas and Happy New Year. Thanks for the detail description. I think Brett might know if the KlassKote thinner would cause a compatibility issue with the Randolph dope. I have used the Preval Spray System (https://www.homedepot.com/p/Preval-Spray-System) for base and clear coats but not epoxy. For this system you need to thin the paint like you would for an airbrush and strain it (I use a simple gauze pad). One power head will do several coats on a Ringmaster size ship, for large ship two heads will do it (you can get extra power heads without the jars).

Happy Holidays to all.     DennisT

Offline 944_Jim

  • 24 supporter
  • Trade Count: (0)
  • Captain
  • *
  • Posts: 854
Re: Clear coating - the final frontier !!
« Reply #10 on: December 25, 2023, 08:14:33 PM »
I read the following at KlassKote. I can see spraying and cleaning will be much like cleaning after dope (make it spotless). Can anyone confirm the long pot time? I take "pot time" to mean this is the mix and use period:

https://www.klasskote.com/faq#Q18
What is the useful pot life (after Parts A & B are mixed) of Klass Kote Epoxy Paint?
Once mixed, this two-component epoxy paint system stays useful (pot life) for several hours only - up to 6-8 hours, all remaining [mixed] paint will harden and be unusable several hours later.

Online Brett Buck

  • Trade Count: (0)
  • Admiral
  • ******
  • Posts: 13741
Re: Clear coating - the final frontier !!
« Reply #11 on: December 25, 2023, 09:35:32 PM »
I read the following at KlassKote. I can see spraying and cleaning will be much like cleaning after dope (make it spotless). Can anyone confirm the long pot time? I take "pot time" to mean this is the mix and use period:

https://www.klasskote.com/faq#Q18
What is the useful pot life (after Parts A & B are mixed) of Klass Kote Epoxy Paint?
Once mixed, this two-component epoxy paint system stays useful (pot life) for several hours only - up to 6-8 hours, all remaining [mixed] paint will harden and be unusable several hours later.

      At normal temperatures, it will gel up in a 6-8 hours as stated. In a cup, it will never ever get rock hard solid, because there is far too much thinner trapped in the cup that will be trapped by the curing paint. I don't necessarily recommend this but you can cover it and put it in the freezer and *maybe* get a second shot at it the next day.

    I am not sure what you mean about "spraying and cleaning". If you mean "cleaning the gun and brush", then it is not like dope, and if you just spray it until it runs clear, the gun will be solidly locked up the next day and you will have to throw it away. You have to disassemble and clean every single part that gets paint on it or through it.

    I have brushed it, it works pretty good that way.

    I note that cleanup can be done with hardware store lacquer thinner.

    I normally do not use the clear epoxy, but it should be admirably bulletproof. The issue is that it yellows over time. I use 3-part automotive urethane. KlassKote also sells a urethane clear kit but I haven't tried it yet.

      Brett

Offline Dennis Toth

  • 2020 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 4228
Re: Clear coating - the final frontier !!
« Reply #12 on: December 26, 2023, 06:00:17 AM »
Brett,
When you brush on the base and color do you need to block sand it flat before the clear? I assume for trim you back mask to minimize weight, do you need to remove tape before it cures out?

Best,   DennisT

Online Brett Buck

  • Trade Count: (0)
  • Admiral
  • ******
  • Posts: 13741
Re: Clear coating - the final frontier !!
« Reply #13 on: December 26, 2023, 10:38:41 AM »

When you brush on the base and color do you need to block sand it flat before the clear? I assume for trim you back mask to minimize weight, do you need to remove tape before it cures out?


     I haven't tried putting clear over brushed paint, but, as a general proposition, I would always sand the color to smooth it out before clear.

      I used to back mask, but for my color scheme, it's not worth it, it saves maybe 1/4 ounce at the cost of another week (a few days to mask, and a few days to set up and travel for painting), so I just paint the whole thing white, then paint colors over it. With certain colors, you need to have some sort of a blocker anyway. White is OK, "Bright Red" or the FS red I used the last time is OK, "Dark Red" is very translucent and you definitely want a blocker underneath - so very little weight is saved by back-masking.

   I don't remove the tape until it has cured to touch at least. There is too high a chance of touching it and screwing it all up. You want to sand the colors anyway, the edges go away in a few swipes of sandpaper. You can sand it reasonably easily for maybe a week at normal temperatures.  After that, it gets so hard that you will really have to lean on it. I normally wait a day or two, knock the edges down, do the next color, etc, until I am done. Then I aggressively wet-sand it.

       Brett

     

Online Brent Williams

  • 24 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 1265
    • Fancher Handles - Presented by Brent Williams
Re: Clear coating - the final frontier !!
« Reply #14 on: December 26, 2023, 11:48:12 AM »
I haven't seen it mentioned yet in this thread, but you'll want to thin (reduce) this stuff if you want a light finish.  It's pretty easy to pork up a plane with this paint if over applied, or at full strength. 
Brett posted a great tutorial on mixing KlassKote: https://stunthanger.com/smf/paint-and-finishing/klass-kote-airbrush-notes/
Laser-cut, "Ted Fancher Precision-Pro" Hard Point Handle Kits are available again.  PM for info.
https://stunthanger.com/smf/brent-williams'-fancher-handles-and-cl-parts/ted-fancher's-precision-pro-handle-kit-by-brent-williams-information/

Online Brett Buck

  • Trade Count: (0)
  • Admiral
  • ******
  • Posts: 13741
Re: Clear coating - the final frontier !!
« Reply #15 on: December 26, 2023, 12:05:46 PM »
I haven't seen it mentioned yet in this thread, but you'll want to thin (reduce) this stuff if you want a light finish.  It's pretty easy to pork up a plane with this paint if over applied, or at full strength. 
Brett posted a great tutorial on mixing KlassKote: https://stunthanger.com/smf/paint-and-finishing/klass-kote-airbrush-notes/

   I think the problem of thinning it takes care of itself, because mixed as recommended (with less than 20% or something thinner) leaves it so thick it comes out like play-doh. I end up something around 1:1:1.5 color/catalyst/thinner or more for spraying. It's less than that for brushing, of course.

     Used properly, an acceptable (to me) finish is roughly 2-3 ounces lighter than an equivalent quality dope job, and infinitely more durable. The difficulty of cleaning up afterward makes it much more difficult in some ways, it is extremely tedious. I am probably going to use all automotive colors and clear for electric, just because the cleanup and ease of use of basecoat color.

      Brett


Advertise Here
Tags:
 


Advertise Here